1. Field of the invention
The present invention relates to a leveling discharge system, and more particularly to such a system for a ready-mix concrete truck which enables the discharge end of a discharge chute thereof to swing transversely of the truck about a vertically maintained axis independently of tipping of the truck.
2. Description of the Prior Art
Existing discharge chutes for ready-mix concrete trucks are adapted to swing transversely of their trucks for distribution of concrete from side to side about preferably upright axes at the mounting ends of such chutes. These axes are vertical when the trucks are transversely leveled, but when, as is frequently necessary, a truck is positioned with a transverse inclination while discharging concrete, the axis is no longer vertical, and the discharge end of the chute is higher when swung to one side of the truck than when swung to the opposite side thereof. This difference in elevation is not only inconvenient because of the possibilities of the chute engaging the surface to be poured at the low side and the splashing of liquid concrete at the high side, but even under relatively favorable conditions this difference in elevation requires raising the heavy concrete filled chute by manual effort as it is swung toward the high side and manually restraining the return of the chute to the low side. This effort required to position the chute frequently requires two or more men, involves great hazard, is inexact, frequently results in the discharge of concrete where it is not wanted, wastes concrete and has for many years been recognized as a serious problem in the delivery of ready-mix concrete and the like where the terrain is not absolutely level.
Existing ready-mix trucks often have the discharge end of the chute elevated or lowered hydraulically so that as the chute is manually swung toward the "high side", the discharge end can be simultaneously lowered relative to the truck so that the discharge end will swing horizontally. While this procedure does reduce the effort somewhat, greater effort and care are required than when pouring on level ground because of the difficulty of synchronizing the elevational movement of the chute with the transverse swinging movement thereof. Even if the effort were reduced to that required on level ground, it would still be necessary to provide an additional man to control the elevation of the chute.
The difficulties arising from varying elevations of the discharge chute of a ready-mix truck which is not transversely leveled as the chute is swung from side to side are, of course, even greater when the truck is moving over an irregular surface while pouring is attempted.